I’m starting to think that CZ must just be full of it by saying that the rifle is designed to handle 5.56 pressures,
Well, the rifle didn't fail and it didn't come apart in your hands, so I would say that your CZ rifle does indeed handle the higher 5.56 pressures.
How far off the lands are you with this Barnes bullet?
What velocity are you getting with these 62gr Barnes loads?
The Ramshot 5.56 data was most likely tested in a 5.56 chamber. The 5.56 has a longer throat than most 223 chambers. Using 5.56 pressure loads in a short throated 223 chamber can cause an increase in pressure.
